Trypanosoma rhodesiense: mitochondrial proteins of bloodstream and procyclic trypomastigotes.

One- and two-dimensional gel electrophoresis of the solubilized mitochondrial proteins of bloodstream and procyclic trypomastigote Trypanosoma brucei rhodesiense and radiolabeling of proteins in the presence of cycloheximide were used to identify proteins synthesized in the trypanosome mitochondrion. The proteins which comprise the mitochondrion were found to be very similar in both bloodstream and procyclic trypomastigotes, but do differ in their level of synthesis. A protein putatively identified as subunit II of cytochrome oxidase (EC 1.9.3.1) was detected in mitochondria from both the procyclic and bloodstream organisms. The presence of this protein in bloodstream trypomastigotes and the overall similarity of protein content in the trypanosome mitochondria is noteworthy in view of the fact that bloodstream trypomastigotes have a repressed mitochondrion with no detectable tricarboxylic acid cycle or cytochrome electron transport chain.